What does the gauge number of a wire primarily indicate?

The gauge number of a wire primarily indicates its diameter. The gauge provides a standard measure that allows for consistent size identification across different wire types. As the gauge number increases, the diameter of the wire decreases, meaning that a lower gauge number corresponds to a thicker wire. This relationship is critical for determining the wire's current-carrying capacity, resistance, and overall suitability for specific applications in electrical systems. Understanding the gauge is essential for ensuring proper wire selection in various electrical and electronic projects, maintaining safety, and achieving optimal performance.